#include<bits/stdc++.h>
using namespace std;
int main(){
	double vegg , vmilk , vtart , e , m , t , num , time;
	cin >> vegg >> vmilk >> vtart;
	cin >> e >> m >> t;
	num = ceil((vegg * e + vmilk * m) / vtart);
	time = ceil(num / t);
	cout << time << endl;
	return 0;
}
